The concept of triangular shaped signs that have three panels for displaying information is known in the are Typically, such signs are found on parking meters and are secured to the parking meter post with some type of an internal clamp. These signs usually display advertising or other information for the viewers. Such signs are useful as information can be viewed from any lateral direction of the sign.
Marker posts are known in the art and are used to place an above ground warning that a pipe line or an electrical line is buried in the soil. The marker posts must be somewhat unobtrusive yet able to warn a person of an underground utility. In addition, the marker posts must be able to withstand the environment for an extended period of time, sometimes twenty years or more. Unfortunately, during the lifetime of the individual marker post, the marker post is oftentimes subject to abuse through accidental contact with machinery working in the area of the marker post. The marker post must be able to withstand such abuse as well as be able to continue to convey a warning message of the existence of an underground hazard to those who may be proximate the marker post. Typically, marker post abuse occurs when vehicles accidentally drive over the marker post. The marker post should remain intact and be able to return to its original erect position after the forces have been removed. One such self erecting marking posts is shown in U.S. Pat. No. 4,343,567 which discloses a self erecting marking post comprised of a cylindrical marking tube that is supported by a cylindrical erecting tube that fits within the marking tube. The two cylindrical members coact to permit the marking post to return to a normal straight condition even though the marking post may be bent over by an object. Unfortunately, cylindrical marking posts do not lend themselves to displaying signs that can be seen from different directions unless separate panels are attached to the cylindrical post. U.S. Pat. No. 4,343,567 discloses that a panel can be attached to the top of the post by rivets. Such attachment of panels by rivets to circular posts is not suitable for long-term use in environmental conditions where wind buffets the sign as the wind can cause the sign to vibrate which eventually causes rivet fatigue that results in the sign falling off the marker.
The present invention provides a triangular shaped resilient one-piece marker post that has three integral information panels that are viewable from different directions. By having the information panels integral with the marker post, the information panels are not subject to separation due to weather or to vandals and can be viewed from different directions.
The marker post is made from materials that are bendable up to 90 degrees without rupture of the bendable material. However, such materials in a flat form do not have sufficient rigidity to allow the marker post to be driven into the ground. To provide the necessary rigidity to the marker post, the materials are formed into a triangular cross-sectional shape so that the marker post can be driven into most soils. In spite of rigidity imparted to the post by forming the marker post into a triangular shape, it has been discovered that a set of internal webs within the marker post coacting with the marker post causes the triangular shaped marker post to return to its normally straight condition even though the marker post may be repeatedly bent. That is, the marker post, which is made rigid by the arrangement of the material in a triangular shape retains sufficient resiliency to return to its upright condition even though the arrangement of the marker post and internal webs imparts rigidity to the marker post to enable the marker post to be driven into most soils.